A study on the resistance of observation systems of observers' expectancies

Different sets of expectations were induced in groups of observers before asking them to observe a film. Four aspects of Hall's notation system for the observation of proxemic behavior (1963) were adopted for the purposes of this study and another observation aspect was added. All Ss observed the same scenes of the film. They only differed in the kind of information on experimenters' beliefs and the hypotheses of the observation study. Results indicate that induced expectancies influenced the recordings of the observers. Implications of these outcomes are discussed.     

Hindsight bias: An interaction of automatic and motivational factors?

If subjects are asked to recollect a former response after having been informed about the correct response, their recollection tends to approach the correct response. This effect has been termedhindsight bias. We studied hindsight bias in an experiment requiring numerical responses to almanac-type questions for physical quantities. We varied (1) the time at which the correct information was provided, (2) the encoding of the original responses by asking/not asking subjects to give a reason for the respective response, and (3) the motivation to recall correctly. We found that hindsight is less biased if reasons are given and if the correct information is provided at an earlier time. Motivation had only interactive effects: (1) With high motivation to recall correctly, the time the correct information was provided had no influence. (2) With reasons given, the variation of motivation showed no effect. These results rule out purely motivational and purely automatic explanations.     

Two studies of Piaget's theory of moral judgment

The relationship between conservation skills and subjective responsibility (SR) in moral judgment was examined in two studies. The Kohlberg ontogenetic priority hypothesis stating that conversation is a necessary but not sufficient condition of SR was pitted against the common structural basis hypothesis advanced by Damon. Piaget's notion of heteronomy as a combination of preoperational thought and unilateral respect was studied by using the behavioural independence tasks by Subbotsky as indicators of unilateral respect. A teaching experiment using Galperin's and Obukhova's method to induce conservation indicated significant transfer from conservation to SR. SR was found to be more susceptible to regression over a 3–month period than conservation. Conservers were less likely to regress on SR than nonconservers. Unilateral respect was related to objective responsibility but not to conservation. Taken together the data fail to support Kohlberg's ontogenetic priority hypothesis and only partially support the Piaget and Damon model of a common underlying structure. It is concluded that SR judgments largely reflect individual judgmental strategies and the effect of conservation on SR is intepreted in terms of increasing cross-situational consistency in the use of these strategies.     

The perception of an optical flow projected on the ground surface

In most experiments in which the importance of visual control on postural stability is studied, optical stimuli attached to vertical surfaces are used. Analyses of long-term standing readjustments generally involve back-and-forth movements of a visual scene or its projection on vertical circular screens. In a natural environment, however, visual information is largely available from the ground. The aim of the experiment reported was to assess the effect of a flow pattern simulating an open outdoor setting on motion perception and postural control. Subjects were presented with an optical texture projected onto the ground. Periods of motionless texture alternated with equivalent durations of unidirectional flows. The change of position of the subject's centre of gravity over time was recorded on a force platform. Results show that the direction of body sway corresponded with that of texture motion. Important aftereffects, as shown in linear vection experiments, were also observed. However, the latency of postural responses was much shorter than with prolonged unidirectional flows produced in other locations of the visual environment. The hypothesis of an ecological specificity of the flows perceived on the ground during terrestrial displacements is discussed.